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The GarageMotorcycle Related Discussion (Yamaha XS650, other makes and models, and anything else motorcycle related including tools and gear)

The engine has ball big end bearings and contains oil passages and ports to ensure needed oil keeps the bearings lubricated. Ball and roller bearings do not need a high pressure oil film to live like babbit type bearings do. Bearing failure in XS650s tends to be related to disuse allowing rust to form rather than wear during use. With reasonable oil changes the bottom end often goes 60,000 miles or more between overhauls.
The manual shows a lubrication schematic and I swear i have seen engine oil distribution art also but can't place my finger on it. So... who was the expert who "informed" you that it's splash?

I was discussing oils, pumps and bearings on another bike forum and a bloke there said "XS 650 big ends survive on a splash feed oil system" I find this hard to believe. I have had very very little to do with Japanese bikes but do believe that they would have a gear pump pumping oil into the crank shaft.

Yes I know that rolling element bearings only require a light stream of oil, drips even, as against plain bearings needing a good flow and pressure. Do XS 650s' have ball or roller BE bearings?

ball bearings

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I actually read this post and now my comment makes absolutely no sense.
Where are we going and why are we in this handbasket.
Hobbies... Avoiding hard work and pain
1987 XLH1100, 1980 XS1100, 1978 SR500, 1980 Yammahopper, 1966 Aermacchi/H-D M-50

The oil gallery across the front of the engine that feeds the oil supply line to the head has ports on the inside of the case that squirt oil on the rod big ends. If you look in Jayel's pic you will see them. Just above the dark line thar shows the oil, just in line with the rods.
The the alternator side and the two center crank bearings get oil pumped to them. The clutch side bearing runs in oil. The oil level is high enough so the crank runs in oil too. This splashes oil up on the botom of the pistons as well as the rods. This helps cool the pistons
The crank being built up out of several parts can not carry oil to the rod big ends.
Leo

The only way you can find out if you can do something is to try.
75 XS650B with a few mods, Dual disc brakes up front, Disc on rear, Pamcopete Ignition with the green coil, Radio Shack rectifier and Chrysler regulator, LED tail/brake and turnsignals. 750 kit,1.5 headepipes, Emgo shorty mufflers.